This document claims priority and contains subject matter related to Japanese Patent Application No. 2001-013648 filed in the Japanese Patent Office on Jan. 22, 2001, and the entire contents of each of which are hereby incorporated herein by reference.
1. Field of the Invention
The present invention relates generally to an image reading device, and more particularly to first and second moving carriages that move in parallel with a contact glass on which an original document is set for reading an image of the original document.
2. Discussion of the Background
An image reading device employed in a copying machine, a facsimile machine, or other similar image forming apparatus, may include first and second moving carriages that move in the same direction at a speed ratio of two to one, in parallel with a contact glass on which an original document is set.
The first moving carriage carries a light source that irradiates an image surface of an original document with light and a first mirror that reflects the light reflected from the image surface of the original document. The second moving carriage carries at least one of a second mirror and a third mirror that reflects the light reflected from the first mirror.
In this type of the image reading device, voltage is applied to the light source from a voltage applying part such as a regulator at a time of image reading. The voltage is applied to the light source through a flexible wiring board connecting the voltage applying part and the light source. Because a flexible wiring board is a relatively expensive part, a manufacturing cost of the image reading device typically increases by use of a flexible wiring board.
The inventors of the present invention realized, as an alternative to a flexible wiring board, a relatively cheap feeding cable including a conductive cable with an outer circumference covered with an insulating film is used, thereby decreasing a manufacturing cost of an image reading device. In a case of using a feeding cable, there may be problems such as a twist in the feeding cable, a tangle of the feeding cable due to a crossing, and a wear of the insulating film due to rubbing against other members.
According to one aspect of the present invention, an image reading device includes a first moving carriage configured to carry a light source that irradiates an image surface of an original document with light and a first mirror that reflects the light reflected from the image surface of the original document, a second moving carriage configured to carry at least one of a second mirror and a third mirror that reflects the light reflected from the first mirror, a voltage applying part configured to apply voltage to the light source, and a feeding cable connecting the voltage applying part and the light source. The feeding cable includes a conductive cable whose outer circumference is covered with an insulating film. The image reading device further includes a first feeding cable holding member fixedly arranged in a vicinity of the voltage applying part at a position along a moving direction of the first and second moving carriages to hold a first portion of the feeding cable at one end side of the feeding cable, a second feeding cable holding member attached to the first moving carriage to hold a second portion of the feeding cable at an other end side of the feeding cable, and a pulley configured to be rotatable in the moving direction of the first and second moving carriages and to move integrally with the second moving carriage. A portion of the feeding cable between the first and second feeding cable holding members is wound around the pulley in a U-shape.
Objects, features, and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.